Hydrogenated cardanol and methods of making the same



. Patented May 26,

HYDBOGENATED GABDANOL AND METHODS F THE SAME Solomon Caplan, New York,N. Y., assimor to -'.lhe Ear-vol Corporation, a corporation or NewJersey No Drawing. original application July 6. 1934,

. Serial No. 73%,986. Divided and this application November 1, 1938,Serial No. 238,165

6 Claims. (Cl. 260-624) The present invention relates to newcompositions of matter and to methods and steps of making and using thesame; and the present invention relates, more particularly, toderivatives of phenols obtained from cashew nut shell liquid and toprocesses oi preparing the same.

Cashew nut shell liquid is described as consisting of about ninety percent of anacardic acid CnHasOa and about ten per cent or cardol,CsaHsaOs, with very small fractional percentages of other materials.

Cashew nut shell liquid has been distilled at a greatly reduced pressureor in a stream oi steam at atmospheric pressure to produce a compoundhaving a molecular weight of 288, a boiling point of 225 C. at about 10millimeters of mercury,

an empirical formula oi CsoHazO, and a probable structural formula ofCuHrzCeHiOH. Characteristics and reactions indicate that this compoundis a phenol with all or parts of the CmHs? atoms together as one radicalin the meta position with respect to the -OH radical and withoneunsaturated bond.

somewhere in the Cal-I21- group of atoms.- This production of the newcompound apparently takes place by the breaking down of the anacardicacid. Hereinafter, the new compound is millimeters of mercury thecardanol comm over uniformly at about 225 C. and when the cardanolitself is dlstilledat ten millimeters oi mercury the'boillng point oiabout 225 C. is constant. Also when the card i. 1;; i di tille 1m cashewnut shell liquid at amospheric pressure while steam is blown through it,for illustrative example at about are 6., the product, cardanol, comesover unliormly, actually in the form of an emulsion, the water of thecondensed steam be= ing dispersed in the new compound.

Due ,to the conditions oi various methods oi removing cashew nut shellliquid from the cashew nut shells, the proportion of cardanol obtainedfrom a elven amount of cashew nut shell liquid varies with the resultingstate or condition of the cashew nut shell liquid. That is to say, inall present commercial methods of obtaining cashew nut shell liquid fromthe cashew the shells for opening them or for expelling the shellliquid'irom the shells, and the degree of temperature at which some ofthese methods are carried out is such that cracking of cashew nut shellliquid occurs with the consequent production of compounds which distillover with the cardanol and which turn dark on exposure to the light.This is a great disadvantage because most of the uses to which cardanolare put require a light color in the final product, for example, incoatings, varnishes, molded compositions, bottlecap paper, electricalinsulation, and

so on. Further, the greater the degree of purity Y of the'cardanol thegreater is the suitability ofthls compound and its derivatives for theiruses. This'disadvantage is overcome either by obtaining the cashew nutshell liquid at normal temperature as-by solvent extraction or bykeeping the nuts at a comparatively low temperature when heating 'toexpell the shell liquid, for example, at below 400 F. The diiilculty isovercome also by changing the darkening compounds which go over with thecardanol into compounds which will not go over with it, as by oxidation,for example. This is done by blowing air .or oxygen through the cashewnut shell liquid beiore distillation of the cardanol or by blowing thecardanol with these same materials before it is redistilled forpurification, this blowing being done preferably with the cashew. nutshell liquid or the cardanol on the alkaline side. This oxidation canalso be effected by'the use of hydrogen peroxide or of bleaching powderor oxidizing agent which will not oxidize the cardano'l,

I have discovered that various derivatives of so siren below togetherwith descriptions of these cardanol can be made which have certaincharacteristics which make them useful in the chemical and other arts.Illustrative examples of methods of preparing derivatives of cardanolare materials. and statements of their uses.

Hydrogenated cordanol A new compound CaoHnO, corresponding to atcardanol butin which the unsaturated bond,

is made by hydrosenating cardanol or by hydro= nuts heat is used, eitherto char or carbonne senatins cashew nut shell liquid before the distiilation thereof either with steam or under reduced pressure at aboutten millimeters of'mercury. This hydrogenation is best carried on bybubbling hydrogen through cashew nut shell liquid or cardanol in contactwith a catalyst at normal or increased pressure and at normal orincreasedtemperature, for example, atabout 180 C. Illustrative examplesof catalysts found to be suitable for this Purp se are copper, nickel,

. palladium black, platinum black, or mixtures of some or all of these,e. g., a mixture of copper and nickel. The catalysts are most efiectivein the finely divided state and/or supported on a carrier such asiniusorial earth.

cardanol ethers By mixing cardanol with di-ethyl sulphate a reaction isobtained which gives ethyl cardanol, presumably according to theformula:

This reaction is carried on in the presence of a sufilcient amount ofNaOH. (or other suitable material) or water solution thereof toneutralize the H2804 which is formed. When dry NaOH is used theequivalent amount of diethyl sulphate is used, but when the watersolution of NaOH is used, twice the equivalent amount of diethylsulphate is necessary because in the presence of water the finalby-product is the sodium ethyl sulphate. Similarly, ethyl chloride canbe used to supply the ethyl group, but the equivalent amount is usedwhether the caustic material is used in the solid or dissolvedformbecausethe intermediate and final by-products are the same in bothcases. Also, ethyl alcohol can be used to supply the ethyl group inwhich case a small amount of sulphuric acid is used as a catalyser. Inevery case heating under a refiux condenser speeds the reaction. whenthe caustic in solution is used the temperature can be about 100 C. andwhen the solid caustic is used the temperature can be higher, forexample, at 150 C. The strength of the caustic solution can be about tenper cent. The resulting ether is separated from the water, solution asby a separatory funnel, washed with water to remove traces of thesolution, and canbe purified by distillation under reduced pressure, forexample, at ten millimeters of mercury.

Characteristics of ethyl cardanol Color ltabil aaaasea Methyl'cardanolis made with di-methyl sulphate, methyl chloride, or methyl alcohol orequivalent thereof and cardanol by methods similar to those used formaking ethyl cardanol.

Methyl cardanol is slightly darker than ethyl cardanol and the color isstable. Likewise, the other alkyl ethers of cardanol can be made by thesame steps. using the corresponding starting compounds.

The corresponding ethers of the hydrogenated cardanol are also made bymethods similar to those used for making the ethers of cardanol.

cardanol esters about 15 grams NaOH in a 15% water solution toneutralizethe HCl formed. Leave the above mixture stand for reaction (exothermic),after which remove the water layer, wash with dilute (or weak) acid tobreak the NaOH emulsion, wash with water, separate the water, anddistill the resulting cardanyi benzoate to purify it.

Characteristics of cardanyl benzcate Cardanyl benzoate has the followingcharacteristics:

Empirical formula. CnHaOr 0-OC-C|H| Structural formula, accepted--. Cdlr(1,3)

Cuiln Index of refraction Ni: 1.5305

lloilingpoint Approx. 290 C. at 7 mm. of

mere! Melting point--- Below 111 nus 20 C.

gpelagific gravity 0.991 at 2PM C.

Color stabillty.... No change in zi hours at C.

Another example of an ester of cardanolv is cardanyl acetate which ismade by reacting acetyl chloride with cardanol, under conditions similarto those described above for the making of cardanyl benzoate, theproduct having the formula,. CHJCOOCBHGC14H31(1,3)

' Acid ethers.

The corresponding acid ethers are made by using, for example,alpha-chlorpropionic acid or chloracetic acid and cardanol to obtaincardanol propionic acid, CuHmCsHaOCzHaCOOI-I or cardanol acetic acid,CuHmCsHaOCHzCOOH, respectively, and hydrochloric acid.

Uses

Hydrogenated cardanol is useful as a pissticiser for cellulose products,for cellulose acetate lacquers, for example; is useful for making lightcolored oil soluble resins. for example, by reaction with formaldehydewith the aid of an acid or alkaline catalyst; and serves as a fixativefor perfumes. Its alkyl ethers, for example the ethyl ether of cardanol,are useful as high boiling liquids for the transfer of heat and for usein two-liquid boilers to replace mercury, theadvantages being stabilityunder heat, extremely high boiling points (above 360 0.), mobility atlow temperatures, relatively low density and nontoxicity.

The ethers of cardanol and also of hydrogenated'cardanoi are useful asplasticisers for cellulose lacquer materials and as flxatives forperfumes.

Cardanol acetic acid ether is a waxy solid 7 which can be used as partor all of the acid for the characteristic reaction with po yhydricalcohol and acid anhydrids to form resins of the alkyd or glyptal type.The advantages of the resins produced are greater resistance to moistureand solubility in drying oils.

The esters of cardanol find a number of uses hitherto not generallycharacteristic of this class of compounds. 'Forexample, cardanylbenzoate has an odor similar to leather, particularly Russia leather,and can be used to give Russia leather odor to other leathers and toartificial leather.

The hydrogenated cardanol, 020E140, and also some of the other cardanolderivatives named above, can be reacted with the aldehydes,formaldelrvde, paraiormaldehyde, hexamethylenetetramine, furiuraldehydeand so on, with or without a catalyst, acid or alkaline. to formcondensation products which can be brought to a resinous state withheat. And these condensation products are light colored and have littleor no odor. The present application is a division of my copendingapplication Serial Number 733.986, filed July 6, 1934, patented November28, 1939, Number 2,181,119.

Having thus described my invention what I claim and desire to protect byLetters Patent is: l. The hydrogenated compound derived from the w: acidconstituent of nut shell liquid having the following formula:

wherein Y stands for the completely hydrogeterial having a melting pointof about 50.5 C. and

a boiling point of about 240 C. at 10 millimeters of mercury.

2. In methods of obtaining the product of claim 1 from material of thegroup consisting of cashew nut shell liquid and cardanol, the step whichcomprises completely hydrcgenating the normally unsaturated aliphaticside chain which is characteristic of the anacardic acid constituent ofcashew nut shell liquid and of cardanol.

3. The method of making hydrogenated cardanol from cashew nut shellliquid which comprises hydrogenating cashew nut shell liquid to satisfythe unsaturated bond in the alkyl side chain of the anacardic acidconstituent with hydrogen and subsequently destructively distilling toseparate hydrogenated cardanol from the residual cardol constituent.

4. The method which comprises hydrogenating to saturation, with the aidof a hydrogenation catalyst, an alkyl phenol which is known as cardanoland which is identified as being obtainable by destructively distillingcashew nut shell liquid at reduced pressure and as having a boilingpoint of about 225 C. at 10 millimeters of mercury, the completelyhydrogenated product having the following structure:

wherein Y stands for the completely hydrogenated normally unsaturatedaliphatic side chain of said cardanol.

SOLOMON CAPLAN.

